1. Field of the Invention
This invention relates to an improved aerodynamic braking system for use in recovering a space vehicle, and more particularly but not by way of limitation, to an improved aerodynamic braking system for use in returning a space vehicle from space and placing it into a low earth orbit where it can be recovered and/or refurbished for reuse.
2. Description of the Prior Art
The development of space technology has enabled the placing of objects in orbit around the earth or at high altitudes about the earth has generated a need for recovery system to return objects to the earth safely. Various schemes have been proposed and actually employed; for example, rigid metal shields have been used to protect an object to be recovered against the heat of air friction, retro-rockets have been used to reduce the rate of descent of objects through the atmosphere and parachute systems have been used to reduce descent velocity during the last stages of descent. The prime disadvantage encountered in the use of prior systems is that they comprised heavy and bulky equipment.
The deployable/retractable aerobrake recovery system of the present invention is useful in the recovery of any of a variety of objects from outer space or the upper reaches of the atmosphere. One of its most important uses is in the recovery of orbital transfer vehicles or rocket boosters. Rocket boosters used to carry satellites or other objects to the upper reaches of the atmosphere or beyond are generally not recovered but are allowed to fall to the earth after use. Such a procedure is very wasteful inasmuch as the boosters are very expensive and contain a large amount of equipment that could be reused. The primary reason why boosters are not recovered is that prior recovery systems were so heavy and bulky that the cost of carrying them with the booster offset the saving in recovering the booster. Furthermore, damage to the booster resulting from landing impact or immersion in water was often extensive. The present invention provides a recovery system which is lightweight and compact so that it is practical to include it with a rocket booster to enable the booster to be recovered in a largely undamaged state and to be reused with a minimum of refurbishment.
The present invention of an improved aerodynamic braking system is particularly adapted for use with an orbital transfer vehicle that may advantageously supported within the cargo bay of a reusable launch vehicle for deployment of the orbital transfer vehicle from the launch vehicle in space. The development of a reusable space launch vehicle, generally referred to as the "space shuttle" provides considerable savings in cost, time and efficiency over earlier expendable launch vehicles.
The space shuttle is limited in orbital heights which can be reached. In order to place payloads in higher orbits, or to go beyond earth orbit, it is necessary that an upper stage, sometimes called the "space tug" be carried into initial orbit in the shuttle, then be deployed and used to carry a payload mounted on the upper stage to the desired location beyond the shuttle orbit. These payloads can include relatively large antenna reflectors of the type employed in communication satellites, earth sensors, navigation sensors, and other devices for precisely orienting the spacecraft.
The space vehicle is supported in the shuttle cargo bay in a manner which will prevent damage to the payload by attenuating loads during shuttle liftoff and abort landings. Greater load attenuation permits lighter and more efficient upper stage and/or payload structures.
The space vehicle support system rapidly and reliably deploys the space vehicle from the stored position within the cargo bay to a location away from the shuttle. Further, the deployment system should be capable of retrieving a space vehicle and returning it to a stored position.
The patented prior art includes U.S. Pat. No. 3,118,636 issued on Jan. 21, 1964 to Arthur R. Kantrowitz et al for a SPACE VEHICLE which disclosed an adjustable drag brake that may be opened and closed as necessary to regulate the flight path, orientation, deceleration, and landing of a man carrying capsule. The Kantrowitz patent however is only directed to the recovery of the space capsule and is not concerned in any respect with the launching device for such capsule.
U.S. Pat. Nos. 4,518,1137 and 4,504,031 were issued to Dana G. Andrews for AERODYNAMIC BRAKING SYSTEM FOR A SPACE VEHICLE and AERODYNAMIC BRAKING AND RECOVERY METHOD FOR A SPACE VEHICLE respectively. These patents disclose a space vehicle that is steered from outer space toward the earth's atmosphere with the main rocket nozzle end first. A jettisonable inflatable braking member is deployed around the vehicle by introducing gas into it. The shape of the inflatable braking bag member may be varied.
U.S. Pat. No. 3,286,951 issued on Nov. 22, 1966 to R. T. Kendall for a RECOVERY SYSTEM discloses a rocket booster provided with a flexible shield of heat resistant material adapted for deployment into a bulbous shape and an inflatable bag attached to the shield and adapted for inflatable disposal partially within the boundaries defined by the shield. The Kendall recovery system is also provided with inflation means for inflating the bag.
U.S. Pat. No. 3,228,634 dated Jan. 11, 1966 and issued to G. Chakoian et al for AIR-DRAG APPARATUS FOR MISSILES relates to an apparatus for use in the retardation and stabilization of airborne missiles. The apparatus includes a jettisonable air braking device attached to a torpedo for slowing the air speed of a torpedo prior to entry into a water body, said air braking device including a plurality of vanes that are deployed by means of an hydraulic circuit after the torpedo has been launched from an aircraft.
None of the above cited patents disclose a light simple easily deployed aerobrake for slowing an orbital transfer vehicle for reentry into the earth's atmosphere that utilizes a plurality of folded ribs that unfold in deployment to support a thermal blanket for protection of the vehicle during reentry.